Tag Archives: trajectory

Before we begin, here’s an update on my good friend Earl “Mac” McDonald, who’s contributed so much to this blog and has enriched my life and the lives of many who participate here. He’s at home, being cared for around the clock by a home-care nursing staff. That will soon transition into home-based hospice care, as his condition will not improve. He knew I came to see him, and we spent a lot of time together in the two weeks I was there. If he could, he would thank everyone who’s sent him good wishes and prayers.

Today’s topic came in about a week ago, and I put it in my bank of reports to write while I’m on the road. Although today is Monday, I’m still traveling home from seeing Mac. The distance was so great that I broke it into a 3-day trip, and was planning to stop by the American Pickers store in Nashville. I got there before they opened, and hundreds of people were already waiting in line to see it. So, I decided to just continue driving home.

The last time we looked at this Quackenbush .308 big bore was when I discovered that my rifle really likes Mr. Hollowpoint’s 68-grain hollowpoint bullet. I also tested a 150-grain Loverin-design bullet that was just a bit too heavy for the gun. It didn’t want to stabilize and was tearing elongated holes in the target at 50 yards.

If you’ll recall, I was running low on air that day, so I could fill the rifle to only 3,000 psi. That gave a stunning group that was smaller than one inch at 50 yards with the 68-grain hollowpoint, but I wondered whether it would do any better if I filled the rifle to higher pressure. I also wondered if going just a trifle faster would have stabilized the 150-grain bullet. There were a lot of unanswered questions after the last test.

It’s been a long time since Part 2 because I was searching for a better bullet for this rifle. Oh, the groups shown in Part 2 aren’t that bad; but when you see what I have to show today, you’ll be glad I stuck with it.

This report is in response to a comment Pyramyd Air got from a customer who doubts that fixed-barrel airguns can ever droop. His position is that they can only have droop if the barrel is heated in some way (as on a firearm that fires very fast) or if the gun is assembled in a shoddy fashion.

He said he believed barrel droop is only commonly found on breakbarrel airguns, which is why he said he would never own one. He thought that droop was mostly caused by the metallurgy of the barrel.

Today, I’d like to address the subject of barrel droop in detail. It can be caused by many things, but poor metallurgy isn’t one of them. Barrels do not bend from cocking, despite what some people may think. It is true that a barrel can be bent by human force, but the force required to do so is much greater than the heaviest cocking effort on the most powerful magnum airgun. So, poor metallurgy is not a contributor to barrel droop.

Today’s report will be quite different from the norm. This is Part 2, which is normally where I test velocity. I did that, and you’ll see it in today’s report — but you’ll also see some targets, because I tested accuracy, too.

When I test a smallbore pellet gun, I know at the start how the gun should perform, more or less. Yes, there are some surprises; and yes, I do make some mistakes — but a lot of what happens can be predicted pretty accurately. But not a big bore!

With a big bore airgun, I’m almost starting from scratch. Sometimes, I will have tested something similar and can use that experience as a starting point, and there’s some of that in today’s report; but this .308 rifle is unlike any other big bore air rifle I’ve ever tested. There are more .308 lead bullet designs and bullet molds available than there are .177 pellet types on the market. Out of all that, I have to select some designs that make sense.

Airgun Academy Links

Search

Search

This pup has teeth!

With 200 ft-lbs. of knockdown power, the .357 Benjamin Bulldog bullpup delivers real knockdown hunting power. When you hunt, you want enough power to do the job…and that's where the Bulldog shines. Plus, its huge 340cc reservoir gets more shots per fill than most other big bores.

4,500 psi hand pump!

You've gotten used to hand pumps that heat up, require time to cool off and stop at 3,000 psi. Time for a change! The Air Venturi G6 hand pump lets you pump up to 4500 psi and can be pumped for hours without heating up. Of course, all pumps require regular maintenance, so we've included enough parts for you to rebuild it 5 times.